Fire extinguisher



April 11, 1944.

C. L. PAULUS ET AL FIRE EXTINQUISHER Filed Oct. 15, 1941 Sheets-Sheet 1 Avvsxvroes CHAELES L .A24u4 US P4 Mo/vo K. 7-007- April 11, 1944.

C. L. PAULUS ET AL FIRE EXTINGUISHER Filed Oct. 15, .1941

2 Sheets-Sheet 2 4. //v us 702 s CHAELES L IDAULL/S Patented Apr. ll, 1944,

FIRE EXTINGUISHER Charles L. Paulus and Raymond K. Stout, Dayton, Ohio Application October 15, 1941, Serial No. 415,070

(Granted under the act of March 3, 1883, as

' amended April 30, 1928; 370 0. G. 357) 1 Claim.

The invention described herein may be manufactured and used by or for Government for governmental purposes, without the payment to us of any royalty thereon.

The invention relates to improvements in fire extinguishers of the type employing a collapsible liquid container adapted to be subjected to a gas pressure-in a sealed casing in such a manner as to cause the container to be punctured and the contents forcibly discharged through a nozzle.

The invention constitutes an improvement in fire extinguishers of the type disclosed in U. S. Patents No. 1,660,713 and No. 1,918,191, and differs thereover principally in the manner of mounting the gas bomb, in the construction and support of the collapsible liquid container, in the provision of a positive seal between the collapsible container and the exterior casing, and in the construction of the puncturing element in the nozzle end of the casing. The invention also includes means for uniting a plurality of individual fire extinguishers and for supporting the group as a unit upon a wall bracket or the like. The fire extinguisher of the present invention retains all the advantages recited in the above mentioned patents, and in addition is superior thereto in the features enumerated, renderin it less expensive to fabricate and more versatile and positive in operation.

he general object of the present invention may therefore be stated to be the provision of an improved fire extinguisher of the type illustrated in U. S. Patents No. 1,660,713 and No. 1,918,191. A particular object is the provision of an improved collapsible liquid container for a fire extinguisher of the type referred to. A further object is to provide an improved sealing means between the collapsible container and the nozzle end of the casing to perform the double function of supporting the container and preventing the escape of gas pressure during the operation of the device. Furtherobjects are to provide an improved casing to increase the efiectiveness of the action of the gas pressur upon the collapsible container, and to provide an improved puncturing element in conjunction with the discharge nozzle. Still another object is to provide means for holding a plurality of fire extinguishers together as a unit, the said means I being designed for releasable engagement with a wall bracket or the like which is subjected to vibration and shocks, as in an airplane.

Additional objects and advantages will become apparent as the description proceeds in connec- 55 tion with the accompanying drawings illustrating a preferred embodiment of the invention.

In the drawings:

Fig. 1 is a broken longitudinal sectional view of a fire extinguisherconstructed according to the present invention and illustrating the upright position in which it is intended to be supported when not in use.

Fig. 2 is a similar view taken at right angles to Fig. 1, after discharge of substantially all the liquid contents, showing the manner in which the container is collapsed under gas pressure to expel the liquid.

Fig. 3 is a perspective view of two fire ,extinguishers attached together as a unitary device for joint or individual operation.

Fig. 4 is a front elevation view of the combined unit shown in Fig. 3 supported upon -a wall bracket or the like.

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4.

Figure 6 is an enlarged sectionalview of a portion of the structure shown in Figure 2.

Figure 7 is an enlarged sectional view of a portion of the structure shown in Figures 1 and 2.

In the illustrated embodiment of the present invention the fire extinguishing liquid is contained in a collapsible container I having a readily puncturable end or head 2 united with the side walls of the container by means of the annular flange 3. The head 2 is concave on the outside and is sufliciently still to normally maintain that shape, for reasons which will be apparent as the description proceeds. Container I may be provided with a filling neck 4 adapted to be sealed by means of a cap 5, or the like, after the container has been filled with fire extinguishing liquid.

Th neck end of the container is constructed to allow for volumetric expansion of the liquid with changes in temperature in order to prevent deformation of the concave head 2 before the device is put in use. This construction may comprise an end wall 6 which is thin in comparison with the end 2, so that upon expansion of the contained liquid the end 6 will be deformed before sumcient internal pressure is developed to deform the head 2; or else the filling neck 4 may be made slightly re-entrant, as shown, to provide an air or gas space over the surface of the liquid when the container is filled. By making the neck 4 re-entrant approximately in the manner shown in the drawings, the container cannot be completely filled, with the result that the trapped air will form a cushioning means "the casing formed by making the wall of the casing thicker in this part, or by securing a separate ring therein. The increased thickness of the end portion of the casing ID will then provide an annular shoulder l2 upon which may be seated the annular flange 3, with a ring-like gasket |3 interposed therebetween. This is the nozzle end of the easing and is adapted to be closed by a cap |4 having a nozzle l5 therein. The cap I4 is preferably adapted for a screw-threaded engagement with the casing l and is provided with an annular shoulder I6 adapted to seat and clamp down upon the flange 3 with sufficient pressure uniformly distributed around the periphery of the flange to form a gas tight seal between the: flange 3 and I0 under reasonable gas pressures within the casing. A second gasket I1 is shown between the shoulder l6 and the flange 3, it being understood that the gaskets H and I3 are provided merely to enhance the effectiveness of the above described seal, and may be dispensed with if the material of the flange 3 is sufficiently yielding to form a gas tight seal between the shoulders I! and IS without gaskets.

As the description proceeds, it will be seen that the flange 3 is intended to perform a double function in the present fire extinguisher, serving first as a positive seal against the escape of gas pressures developed within casing Ill, and serving further as a means of support for the weight of the container I and its contents when the fire extinguisher is supported in a vertical position with the nozzle end uppermost. The nozzle I is provided with a puncturing element |8 which will later be described in greater detail, and which is adapted to puncture the end wall 2 in the operation of the fire extinguisher. To prevent the accidental puncturing ofthe end wall 2 the device is designed to normally be supported in a vertical position so that the weight of the liquid will have no tendency to bring the end 2 into premature contact with the puncturing element l3, even under conditions of extreme vibration such as might be encountered in an airplane. The concavity of the end wall 2 is sufficient to leave a considerable space between it and the puncturing element l8 when the flange 3 is clamped in place, as shown in Fig. 1.

The other end of the casing I0 is closed by a cap carrying a screw-threaded hollow nipple 2| adapted to threadably engage a receiver 22 for a cartridge, gas bomb, or capsule 23 of gas pressure producing material. In the illustrated embodiment the capsule 23 preferably contains a compressed gas retained in the capsule by a metallic sealing disc 24 in the reduced neck portion 25. The neck portion 25 is adapted to form a gas tight seal in a resilient sealing ring 23 with the metallic disc 24 adjacent a hollow piercing point 21 which communicates with the axial passageway 2B. Lateral passageways 29 may be provided if desired to communicate with the interior of the casing ID,

The receiver 22 is provided with a rounded seat 30 to receive the hemispherical end of the cartridge or capsule 23. By screwing the receiver 22 farther onto the nipple 2| the hollow puncturing pin 21 will be forced through the metallic disc 24 to release the compressed gas within the 1 capsule 23 and establish a relatively high. gas

pressure within the casing I0 suificient to collapse the side walls of the container I. It will be seen that by virtue of the thick end portion extending inwardly of the casing ID the container I will be spaced on all sides from the inner surface of the casing ID to allow complete freedom of action for the compressed gas to react simultaneously against all sides of the container.

In the operation of the device for fire extingushing purposes the building up of the gas pressure within the casing I0 first tends to deform the side walls of the container producing a liquid pressure therein sufficient to utilize the full effectiveness of the previously mentioned expansion means. After no more liquid displacement can occur in this manner, it being remembered that the end Wall 6 is subjected on its outer surface to the same gas pressure as the cylindrical body of the container the concave end wall 2 will be bulged outwardly with a snap action against the cap l4 and the puncturing element l8, since the only reaction against the outside surface of the end wall 2 is that of atmospheric pressure. The puncturing of the end 2 will cause the fire extinguishing liquid to be discharged under pressure through the nozzle I5 until the liquid supply is substantially exhausted, due to ,the progressive collapsing of the side walls of the container I under the high gas pressure developed within the casing Ill. The walls of the container are made of a material which is sufflcientl deformable to permit substantially the complete collapse of the container, effective to remove practically all of the liquid therein. Fig. 2 shows the container approaching the final stage of collapse, just prior to the discharge of the last of the expellable liquid.

The efliciency of this type of fire extinguisher is found to depend primarily upon the effectiveness of the seal effected between the flange 3 and the casing l0, and the seal between the neck 25 of the gas capsule and the sealing ring 26; and the construction of the former seal constitutes one of the most important improvements over the fire extinguishers in the above mentioned patents.

The nipple 2| is preferably provided with a centering and supporting cup-like element 3| adapted to receive and support the cap portion 5 of the liquid container. This additional supporting means is not necessary for small capacity containers, but is desirable where the container holds a considerable weight of liquid and is subjected to excessive vibration. In small fire extinguishers, not subjected to excessive vibration, the annular flange 3 may be made sufllciently strong to safely hold the container l in the casing without additional means of support for the neck end of the container. objects of the invention may be accomplished by container I having a different form of neck end at 4 and 6, so that the neck 4 and cap 5 may be dispensed with in-lieu of other sealing means. Also, if the container is filled and sealed by some other. means than the neck 4 and cap 5, some other type of supporting means may be provided at 3|, if desired, to co-operate with the particular type of container employed.

The present invention further comprises an improved puncturing element l8 in conjunction with the nozzle l5, as shown in Figs. 1 and 2.

Thus the principal The puncturing element 18 is shown here to be generally conical in shape with a fluid passageway 35 offset a slight amount from the axis of the cone so that its inner end forms a generally oval aperture 36 at one side of the tip 31. A surface 38 is then formed around the aperture 35 and extending substantially to the apex 31 in the manner illustrated, this surface 38 being preferably slightly hollow ground to provide sharp edges where it intersects with the surface of the cone and to provide a space which might be described as a concavity or depression extending inwardly of the surface of the cone around the margins of the aperture 36. When this type of puncturing point protrudes through the end wall 2 in the manner illustrated in Fig. 2 it is found that there is less tendency for the material of the end wall 2 to be pressed fiatly against the aperture 36 so as to interfere with the discharge of liquid. The specific puncturing point above described renders fire extinguishers of this type more certain in operation by tending to reduce the possibility of failure through sealing of the discharge opening.

Another feature of novelty in the present invention comprises means for-rigidly uniting a plurality of the above described fire extinguishers. Besides having the obvious advantage of doubling the capacity of a single fire extinguishing device, the uniting means also results in increased utility and provides a convenient support for carrying fire extinguishers on a wall bracket or the like, such as is indicated generally at 40 in Figs. 4 and 5. The wall bracket comprises an outstanding arm 4| having an aperture or slot 42 in the top surface thereof for receiving a downwardly extending projection or tongue, on a means for uniting a pair of fire extinguisher casings. The wall bracket also carries a pair of outstanding spacing plates 43, and a spring finger 44 for releasably engaging another part of the uniting means to hold the pair of fire extinguishers releasably in a fixed upright position on the wall, safe from casual displacement even though subjected to severe vibration.

The means for uniting a pair of fire extinguishers in the present embodiment comprises a pair of clamping elements 45 and 46 embracing the casings l0 and I0 near their ends, as shown. '"fne clamping means 45 carries a curved tongue 4? intermediate the casings, this tongue being adapted to enter the opening or slot 42 to centrally position the clamping member 45 on the outstanding arm 4|. A projection 48 carried by the clamping band 45 is adapted to be engaged by the spring finger 44 so as to hold the tongue it firmly seated in the slot 42 and at the same time hold the receivers 22 and 22' in firm contact with the spacing plates 43. The above described supporting means holds the fire extinguisher combination securely in an upright position against casual displacement from vibration, shock, or the like, but at the same time renders the device readily accessible by merely lifting the spring finger 44 to clear the projection 48 and then lifting the fire extinguisher unit upwardly to raise the tongue 41 out of the slot 42. When the fire extinguishers are supported vertically, as shown in Figs. 1 and 4, the weight of the liquid in the container I will be suspended from the annular flange 3, and will receive additional support from means. 3|, so as to relieve the concave end 2 of all weight or stress which might prematurely bulge it outwardly into contact with the puncturing element l8.

It will be remembered that each of the pair of fire extinguishers shown clamped together in simultaneous operation if a large quantity of fire extinguisher liquid is found to be necessary, but if the fire can be quenched with the contents of but one of the extinguishers excessive discharge of the liquid can be avoided. Also, if the fire is of such a nature as to require the sudden application of fire extinguishing liquid at a faster ,rate than it can be discharged from a single fire extinguisher, the contents of both extinguishers l0 and Ill may be directed simultaneously to the source of the blaze and might in this manner succeed in smothering a fire which could not be quenched by a single stream. It is, of course, also within the scope of the invention to design the clamping or uniting means 45 and 46 to support three or four individual fire extinguishers in stead of oniytwo as shown. The advantage of playing a plurality of streams upon a fire simultaneously, together with the advantage of onehanded operation of the device is of especially great importance in fighting fires aboard an airplane or other vehicle carrying large quantities container having two ends, one end being readily puncturable and concave on its outer surface, said one end having an annular flange therearound, the central portion of the other end of said container being pressed inwardly to form an annular circumferential air pocket therein which will allow the liquid in said container to expand without bulging said concave surface, means in saidcasing to clamp said flange so as to support said container and to provide a substantially gas tight seal between said flange and said container, a nozzle on said container, puncturing means communicating with said nozzle and normally spaced from said readily puncturable end, said puncturing means being adapted to puncture said end when the latter is caused to bulge outwardly, andmeans to create a gas pressure within said casing sufficient to collapse the sides of said container and cause said readily puncturable end to be punctured to discharge said liquid through said nozzle.

CHARLES L. PAULUS. RAYMOND K. STOUT. 

